全文获取类型
收费全文 | 1655篇 |
免费 | 10篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 44篇 |
化学工业 | 45篇 |
金属工艺 | 14篇 |
机械仪表 | 11篇 |
建筑科学 | 9篇 |
能源动力 | 5篇 |
轻工业 | 25篇 |
水利工程 | 1篇 |
无线电 | 73篇 |
一般工业技术 | 59篇 |
冶金工业 | 1192篇 |
原子能技术 | 10篇 |
自动化技术 | 180篇 |
出版年
2018年 | 3篇 |
2017年 | 9篇 |
2016年 | 7篇 |
2015年 | 3篇 |
2014年 | 4篇 |
2013年 | 32篇 |
2012年 | 9篇 |
2011年 | 18篇 |
2010年 | 13篇 |
2009年 | 13篇 |
2008年 | 16篇 |
2007年 | 16篇 |
2006年 | 17篇 |
2005年 | 17篇 |
2004年 | 13篇 |
2003年 | 11篇 |
2002年 | 13篇 |
2001年 | 7篇 |
2000年 | 19篇 |
1999年 | 40篇 |
1998年 | 319篇 |
1997年 | 214篇 |
1996年 | 159篇 |
1995年 | 84篇 |
1994年 | 69篇 |
1993年 | 67篇 |
1992年 | 20篇 |
1991年 | 29篇 |
1990年 | 21篇 |
1989年 | 33篇 |
1988年 | 24篇 |
1987年 | 35篇 |
1986年 | 25篇 |
1985年 | 26篇 |
1984年 | 10篇 |
1983年 | 12篇 |
1982年 | 13篇 |
1981年 | 13篇 |
1980年 | 21篇 |
1979年 | 8篇 |
1978年 | 14篇 |
1977年 | 32篇 |
1976年 | 75篇 |
1975年 | 6篇 |
1974年 | 5篇 |
1973年 | 9篇 |
1972年 | 6篇 |
1971年 | 5篇 |
1969年 | 5篇 |
1966年 | 3篇 |
排序方式: 共有1668条查询结果,搜索用时 687 毫秒
1.
Ching-Te Chuang Bernstein K. Joshi R.V. Puri R. Kim K. Nowak E.J. Ludwig T. Aller I. 《Circuits and Devices Magazine, IEEE》2004,20(1):6-19
The generation-over-generation scaling of critical CMOS technology parameters is ultimately bound by nonscalable limitations, such as the thermal voltage and the elementary electronic charge. Sustained improvement in performance and density has required the introduction of new device structures and materials. Partially depleted SOI, a most recent MOSFET innovation, has extended VLSI performance while introducing unique idiosyncrasies. Fully depleted SOI is one logical extension of this device design direction. Gate dielectric tunneling, device self-heating, and single-event upsets present developers of these next-generation devices with new challenges. Strained silicon and high-permittivity gate dielectric are examples of new materials that will enable CMOS developers to continue to deliver device performance enhancements in the sub-100 nm regime. 相似文献
2.
FC Breedveld 《Canadian Metallurgical Quarterly》1997,141(15):717-719
Slow-acting antirheumatic drugs (SAARDs) are usually prescribed in rheumatoid arthritis only when non-steroid anti-inflammatory drugs can no longer suppress the inflammation or when articular damage is radiologically apparent. It was established recently that articular damage occurs in an early phase of RA. This damage is linked to subsequent disability; to prevent it is the purpose of SAARDs. In view of the short-term reduction of arthritis activity and improvement of function as well as the meanwhile established fact that the side effects of SAARDs are not different from those of other antirheumatic agents, SAARDs should be prescribed in an early phase of RA. 相似文献
3.
4.
W. S. Walston I. M. Bernstein A. W. Thompson 《Metallurgical and Materials Transactions A》1991,22(6):1443-1451
The microstructure of a single-crystal nickel-base superalloy, PWA 1480, has been varied by heat treatment and hot isostatic
pressing in order to study the role of the γ/yγ′ eutectic and porosity on subsequent tensile behavior. The level of porosity
was found not to affect any of the tensile properties, while the γ/γ′ eutectic strongly influenced ductility. Eliminating
the γ/γ′ eutectic increased ductility which was attributed to the cleavage fracture of this constituent. It is proposed that
such cleavage of the γ/γ′ eutectic is initiated by the stress created from impinging slip bands, promoting shear localization,
and final fracture along {111} slip planes. The precise nature of this fracture process is discussed with emphasis on the
role of the γ/′ micro-structure. The deformation structure of PWA 1480 was also studied, and while different in some respects
from many other single-crystal superalloys, its fracture process appears to be similar.
Formerly Graduate Student, Department of Metallurgical Engineering and Materials Science, Carnegie Mellon University. 相似文献
5.
6.
7.
8.
JF DeFrance S Sands FC Schweitzer L Ginsberg JC Sharma 《Canadian Metallurgical Quarterly》1997,9(4):283-293
The purpose of this article is to deliberate the moral and legal dilemma entailed in the weapon of the labour strike as a pressure tactic on the Israeli Finance Ministry regarding job slots, budgets and, in effect, violating the collective agreement signed by the nurses and impairing patients' treatment, as opposed to refraining from striking and suffering the heavy burden of work, the lack of trained personnel, low wages, and the inability to give patients proper, high quality treatment. 相似文献
9.
10.
MS Ali PP Sayeski LB Dirksen DJ Hayzer MB Marrero KE Bernstein 《Canadian Metallurgical Quarterly》1997,272(37):23382-23388
Angiotensin II is the effector molecule of the renin-angiotensin system. Virtually all of its biochemical actions are mediated through a single class of cell-surface receptors called AT1. These receptors contain the structural features of the seven-transmembrane, G-protein-coupled receptor superfamily. Angiotensin II, acting through the AT1 receptor, also stimulates the Jak/STAT pathway by inducing ligand-dependent Jak2 tyrosine phosphorylation and activation. Here, we show that a glutathione S-transferase fusion protein containing the carboxyl-terminal 54 amino acids of the rat AT1A receptor physically binds to Jak2 in an angiotensin II-dependent manner. Deletional analysis, using both in vitro protocols and cell transfection analysis, showed that this association is dependent on the AT1A receptor motif YIPP (amino acids 319-322). The wild-type AT1A receptor can induce Jak2 tyrosine phosphorylation. In contrast, an AT1A receptor lacking the YIPP motif is unable to induce ligand-dependent phosphorylation of Jak2. Competition experiments with synthetic peptides suggest that each of the YIPP amino acids, including tyrosine 319, is important in Jak2 binding to the AT1A receptor. The binding of the AT1A receptor to the intracellular tyrosine kinase Jak2 supports the concept that the seven-transmembrane superfamily of receptors can physically associate with enzymatically active intracellular proteins, creating a signaling complex mechanistically similar to that observed with growth factor and cytokine receptors. 相似文献